Spectroscopy Lab: Multiple Choice Practice Quiz

A collection of flashcards designed to help students review key concepts from the Spectroscopy Lab multiple choice practice quiz.

What type of lamp is used in the Cary 60 UV-Vis?

Deuterium

What is the purpose of the monochromator?

Select the desired wavelength

Which part holds the sample in place?

Sample holder/cell compartment

Which component measures the amount of transmitted light?

Detector

Which of the following is not part of the optical path?

Pump

What is the correct equation for Beer's Law?

A = εcl

Absorbance is related to transmittance by:

A = -log(T)

If the cuvette path length increases, absorbance:

Increases

What does ε represent in Beer's Law?

Molar absorptivity

Beer's Law only holds at:

Low-to-moderate concentrations

What is plotted on the y-axis in a calibration curve?

Absorbance

What is on the x-axis in a calibration curve?

Concentration

The slope of the calibration line equals:

Detector response

If a standard has A = 0.300, and slope is 0.100, what is the concentration?

3.00 ppm

A linear calibration curve ensures:

Accurate prediction of unknowns

What type of cuvette is ideal for UV region?

Quartz

Why must cuvettes be wiped before inserting?

To remove fingerprints/oil that interfere with light

The blank solution should:

Contain only solvent

The purpose of the blank is to:

Zero out background absorbance

Standards must be prepared by:

Accurate dilution using volumetric tools

The most sensitive wavelength to detect an analyte is:

Lowest peak

What happens if you measure away from λmax?

Lower sensitivity

The Cary 60 software allows you to:

Choose method, read absorbance, export data

You must re-blank when:

Changing wavelength or solvent

%T stands for:

% transmittance

LOD stands for:

Limit of detection

LOQ means:

Limit of quantitation

A cuvette placed backwards might cause:

Scattered or inaccurate results

R-squared (R2) in calibration tells you:

Goodness of fit

If you forget to blank before measuring standards:

All absorbances will be offset/inaccurate